World War Z is out now on Blu-ray and DVD and this is one of those rare instances where watching the Unrated version makes a big difference: Brad Pitt’s thriller about a worldwide Zombie pandemic adds seven extra minutes of more intense (but not that gruesome) footage, scenes that significantly ratchet up the suspense from the PG-13 version that played in theaters.

Pitt’s character is a former United Nations investigator who’s drawn back into service because he’s apparently the only guy they trust to deal with the problem. Of course, he needs military support for his mission and, as always when there are guns and uniforms, Hollywood needed some military technical advisors to help get things right.

Retired USMC Sgt. Freddie Joe Farnsworth was the lead advisor on World War Z and he talks about his role and his long history working with Brad (Spy Game!) in the clip below.

World War Z is an odd attempt at making a blockbuster. Like most Hollywood guys approaching middle age, Pitt likes to talk about his love of ‘70s political thrillers; he’s trying to hide one of those inside a popcorn movie about the undead. There aren’t many closeups of brains being eaten, so this one might not appeal to Night of the Living Dead fans.

A better comparison might be to Contagion, Steven Soderbergh’s flu epidemic movie from last year. Swap in zombie infections for flu and you get the same kind of scientific-research-saves-the-world thriller.

The novel that inspired the movie was an oral history of the zombie wars, one that told the story from multiple points of view. The end of World War Z suggests that sequels could retell the story with completely different sets of characters. That’s potentially a more interesting approach than trying to wring more plot from a guy who’s already helped save the world and been reunited with his family.

The Unrated film is definitely a better version than the theatrical release. Odds are good that it’s the theatrical one that’ll turn up later on cable. If you’re into buying the digital version, you can have your choice of either one at $20 each. For that price, you can get the Blu-ray/DVD combo and have both versions of World War Z (along with a digital copy of the theatrical cut).